Trump is what I like to call balance sheet rich...that is he has heavy assets in non-liquid or non-tangible assets like Land/Property and more important Goodwill. Considering Trump is basically a brand (he license most of his "name" out like a Burger King Franchise and actually has no operational stake in them) on top of his fluctuating "how much he's worth" I promise you there is a significant amount of his "money" is in Goodwill. For those who don't understand what the accounting term for Goodwill is it is when a company acquires another at a higher cost than what its actually worth to account for its branding, patents and customer base. In the US though this basically comes down to branding/patent protection and how much these "assets" have to the company, that if lost, would hurt its value. This would also help explain why his "wealth" can fluctuate because Plant/Property/Land and non-tangibles as Goodwill are appraisal based and with the value of it being interpreted by a human you can easily inflate what is worth if you manage to slip a few dollars while nobody is looking.
I would love to see Trump's tax returns only to see that he has a very low cash flow compared to what he claims to be. If I had to guess based on the way he acts, how "franchising" fees work and all non other sources of income I have no doubt he is worth less than 200 million in liquid assets. Still a fair amount to be truthful but compared to what Fred Trump was worth and all the "loans" Trump was given he would have been better off just throwing them into a CD when interest rates were closing in to 20% (I think it got up to 18%? I should look it up but meh).